Pneumatic steering device



April 5, 1938, c. JL HUG PNEUMATIC STEERING .DEVICE Filed Nov. 2, 193e:5 sheets-sheet 1 April 5, 193s. c, J, HUGA 2,112,962

PNEUMATIC` STEERING DEVICE Filed Nov. 2, 1936 5 Sheets-Sheet 2 April 5,193s. g. HUG 2,112,962v

l' PNEUMATIG STEERING DEV-ICE 5 Sheeis-Sheet 3 Filed NOV. 2, 1936Patented Apr. 5, 1938 UNITED STATES PATENT OFLFLlf-CE 3 Claims.

My invention has relation to improvements in steering devices for motorvehicles, especially trucks, and it consists in the novel features ofconstruction more fully set forth in the speciiieation and pointed outin the claims.

The invention is primarily concerned with a pneumatic steering device asan auxiliary to the customary steering apparatus controlled from thesteering wheel by manual operation of the driver; and it has for itsprincipal object the interposing of pneumatically operated connectionsbetween the steering wheel and the front wheels of the vehicle which`may be either pedally or manually actuated by the driver to assist himin the steering of the vehicle.

A further object of the invention is to apply such pneumatic mechanismto the standard connections associated with the steering wheel so as toavoid unnecessary multiplicity of parts, and at thesame time maintain'asimple, durable and emcient apparatus.

These objects, as well as others inherent in the invention, will bebetter apparent from a detailed description thereof in connection withthe accompanying drawings, in which:

- elevation of the steering stair and a fragment of the steering wheelmounted thereon, together with the control lever, control pedal andvalve of the pneumatic steering apparatus; Fig. 5 is a verticalsectional detail taken on the line 5-5 of Fig. 4 showing pedal forcontrolling the pneumatic steering in front elevation; Fig. 6 is avertical cross sectional detail taken on the line 6 6 of Fig. 5; andFig. 7 is a cross sectional detail through the control valve for thepneumatic steering.

Referring to the drawings, T represents a truck in the cab C of which isthe usual steering stair l, on the upper end of which is a steeringwheel 2 and at the lower end of which is a steering arm 3. The steeringarm 3 is connected by means of a rearwardly extending rod 4 to the upperarm 5 of a double lever, the lower arm 6 of which is connected by asteering rod 1 to a front wheel 8. These steering connections are old inthe art and form a part of the present in- (ol. 18o-479.2)

vention onlyfin so far Aas lthe pneumatic mechanism is associated withthem.

In the present instance, the lever comprising the arms l5 and '6,projecting Vfrom the hub 9, has formed integrally with it a short leverI `(which-also projects from the hub9) so that the leve-r will oscillatein unison with the lever arms and B.

The hub 9 of said lever arms is mounted for rotation on theprojectingportion II of a pin I2 carried by a. housing VI3 bolted or otherwisesecured to the flanges of cne'of the frame members I4 ofthe truck T.Similar cylinders I5, I5 are mounted uponbrackets I5, I6 projecting fromand Vfixed to the frame member I4 and within each cylinder is an elasticdiaphragm I1 which divides the-cylinder into two compartments a and h. Aconnecting rod I8 traverses the cylinder I5 and has a mushroom head I9in contact with `the diaphragm 'I1.` The outer ends of connectying rods|18, I8 are pivotally connected to the' short lever I0 so that the rodsI8, I8 and said lever Il) will operate in unison. -An air compressor 2Uis mounted adjacent to the engine and isvdriven therefrom. The drivingconnections are not shown as this practice is-a common expedient in theart. A tube 2| leads from the high pressure side of the air compressorto a T 22, one branch of the T being connected by a tube 23 to an airreservoir 24 and the other branch of the T 22 being connected by a tube25 to a rotary valve 26 mounted in valve casing 21. There are two tubes,28 and 29, leading from the valve 26 by means of short ports 28 and 29',respectively, and leading tothe air chambers a, of their respectivecylinders I5. The valve 26 is provided with a port 30 so arranged thatwhen the valve is rotated in one direction, tube 25 will be connectedwith tube 28; and when the valve is rotated in the opposite direction,tube 25 will be connected withtube 29. Obviously, in lbetween these twopositions neither tube 28 nor tube 29 will be connected with tube 25 andthe valve will be closed. The valve 26 is also provided with an exhaustport 26 communicating with port 21 in casing 21 so that when pressure isapplied to one of the cylinders I5, the air may exhaust from the othercylinder through ports 26 and 21.

The valve has an operating lever 3| projecting in a horizontal positionwhen the valve is closed,- the outer end of said lever being connectedby a rod 32 to a strut 33, forming a part of valve operating pedal 34.The pedal 34 has inwardly extending lateral flanges 35, 35 which havealigning openings o, o so that the pedal may be pivotally connected bymeans of bolts 36, 36 to side members 31, 31 of a U-shaped bracket 38. Aplate 39 is welded or otherwise iixed between the side members 31, 31 ofbracket 38 in an inclined position so as to be parallel with the pedal34 when said pedal is in its position of rest with the control valve 26closed, and a pair of coiled springs 49, 40 are mounted over bolts 4|,4l on opposite sides of the pivotal axis of `the pedal 34. 'Ihe springs40, 40 are always under compression and since their lower ends bearagainst the plate 39, they serve to hold the pedal 34 in itsintermediate or at rest position. Irrespective of which Way the pedal 34is rocked, one of the springs will be compressed and the other willexpand so that just as soon as the pressure is removed from the pedal,the springs will equalize and restore the pedal to the position shown inFig. 6. This is important since this position of the pedal insures theclosing of the control valve 26.

The valve 26 may also be manually controlled by means of a hand lever 42pivotally mounted by means of a bolt 43 on a collar 44 fixed to thesteering staff i, the front-end of lever 42 being connected. to thestrut 33 by means of a rod 45 so that upon rocking the lever 42, thestrut 33 and pedal 3d will also be rocked to actuate the control valvelever 34 and open the valve to admit air either to tube 28 or tube 29.

By this time it should be obvious that when the valve 26 is operated toadmit air from the reservoir or compressor to the tube 28, the righthand cylinder I will actuate the short lever I0, together with the leverarms 5 and 6, to steer the truck in one direction; while on the otherhand, when air is admitted to the tube 29, the left hand cylinder I5will actuate the lever l0 so as to steer the truck in the oppositedirection.

My improved pneumatic steering device is not intended to completelysteer the truck of itself but is merely to assist in the manual steeringunder such conditions when the operator would have diiculty in steeringthe truck solely by hand.

I claim:

1. In combination with the steering mechanism of a motor vehicle,including an oscillating lever between the steering wheel and thevehicle wheels, an auxiliary steering device comprising oppositelydisposed air cylinders, plungers associated therewith and operable byair admitted to said cylinders, said plungers having connection withsaid oscillating lever, a source of compressed air, means connectingsaid source of air with said cylinders, a control valve for selectivelycontrolling the action of the air on said plungers, means independent ofthe steering wheel for actuating said control valve, and means eiectiveon the actuating means for automatically restoring the actuating meansto neutral position after having operated the control valve.

2. In combination with the steering mechanism of a motor vehicle, anauxiliary pneumatic steering device including an air control valve, apedal and a hand lever interconnected with the control valve wherebyeither may operate said control valve, and means for automaticallyrestoring said control valve, p edal and hand lever to at rest positionafter operation of either pedal or hand lever.v

3. In a motor vehicle, the combination with the front wheels thereof, ofa steering device, comprising an actuating lever, a steering wheel andsuitable mechanical connections between said steering wheel, lever andfront wheels, a pneumatically operated plunger on each side of saidlever and connected thereto, a source of compressed air, `means forconducting said air to the plungers, a controlling valve for selectivelycontrolling the action of the air on said plungers, and a rocking leverconnected to said valve, said lever having a plurality of equalizingsprings effective thereon for maintaining the lever in an invariableposition when the controlling valve is closed.

CHRISTIAN J. HUG.

